The invention relates to a single-shell helmet made from foamed plastic and a process for the production thereof.
For example US suppliers refer to such a helmet as a soft-shell helmet. Such helmets comprise a polystyrene-base foamed plastic and in particular Styropor. These helments comply with the ANSI standard and are conventionally given a textile covering for individual colouring purposes.
The major disadvantage of such helmets is that as a result of their closed, one-piece form, they take up a relatively large packing volume. In addition, such helmets do not have adequate flexibility for adapting to different head sizes. This adaptation has hitherto been achieved by two or three generally different helmet sizes, the finer adaptation taking place by applying soft material cushions to the inner surface of the helmet. The helmet has conventionally been fixed by means of a chin strap with a chin strap triangle.
Other protective helmets for racing cyclists are in particular constructed in two-shell form generally involving the combination of an inner rigid foam shell and an outer shock-proof plastics material shell.
An example of the latter helmet is known from DE 36 32 525 A1. However, this helmet only has a web-like, inner head protection made from flexible foamed plastic, whose size can be adjusted at the back of the head, e.g. using burr fastenings. However, from the safety standpoint, an outer rigid shell is placed over the skull. In another protective helmet, such as is known from DE 31 29 199 A1, use is made of an outer helmet shell made from shock-proof plastic with a soft inner cushioning.
However, also in the case of the last-mentioned helmets, the problem of the large packing volume, inadequate adjustability and adaptation to different head sizes still exist.
While taking into account of these disadvantages of the prior art, the problem of the present invention is to provide a helmet in a simple form with a high adaptation for comfort and while retaining the safety aspects, at the same time achieving a relatively flat packing volume and enabling production in one process step.